U.S. patent application number 17/605225 was filed with the patent office on 2022-06-09 for wire shape measurement device, wire three-dimensional image generation method, and wire shape measurement method.
This patent application is currently assigned to SHINKAWA LTD.. The applicant listed for this patent is SHINKAWA LTD.. Invention is credited to Takaya KINJO, Hiroshi MUNAKATA, Shota NAKANO, Akira SEKIKAWA.
Application Number | 20220180494 17/605225 |
Document ID | / |
Family ID | 1000006199892 |
Filed Date | 2022-06-09 |
United States Patent
Application |
20220180494 |
Kind Code |
A1 |
KINJO; Takaya ; et
al. |
June 9, 2022 |
WIRE SHAPE MEASUREMENT DEVICE, WIRE THREE-DIMENSIONAL IMAGE
GENERATION METHOD, AND WIRE SHAPE MEASUREMENT METHOD
Abstract
Provided is a wire shape measurement device of a semiconductor
device comprising a substrate, a semiconductor element, and a wire
connecting an electrode of the semiconductor element to an
electrode of the substrate. The wire shape measurement device
comprises: cameras that capture two-dimensional images of the
semiconductor device; and a control unit that examines the shape of
the wire based on the two-dimensional images of the semiconductor
device acquired by the cameras. The control unit performs pattern
matching using information on the position at which the wire is
connected to the substrate or the semiconductor element and
thickness information of the wire, and by utilizing the pattern
matching, the control unit: generates a three-dimensional image of
the wire from the two-dimensional images of the semiconductor
device acquired by the cameras; and performs shape measurement of
the wire based on the generated three-dimensional image of the
wire.
Inventors: |
KINJO; Takaya; (Tokyo,
JP) ; NAKANO; Shota; (Tokyo, JP) ; SEKIKAWA;
Akira; (Tokyo, JP) ; MUNAKATA; Hiroshi;
(Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SHINKAWA LTD. |
Tokyo |
|
JP |
|
|
Assignee: |
SHINKAWA LTD.
Tokyo
JP
|
Family ID: |
1000006199892 |
Appl. No.: |
17/605225 |
Filed: |
April 7, 2020 |
PCT Filed: |
April 7, 2020 |
PCT NO: |
PCT/JP2020/015653 |
371 Date: |
October 20, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06T 7/62 20170101; G06T
7/55 20170101; G06T 2207/30244 20130101; G06T 2200/04 20130101;
H04N 5/247 20130101; G06T 2207/30148 20130101; G06T 7/70 20170101;
H01L 24/48 20130101; H01L 2224/4809 20130101; H04N 13/156 20180501;
G06T 7/001 20130101 |
International
Class: |
G06T 7/00 20060101
G06T007/00; H04N 13/156 20060101 H04N013/156; G06T 7/55 20060101
G06T007/55; G06T 7/62 20060101 G06T007/62; G06T 7/70 20060101
G06T007/70; H04N 5/247 20060101 H04N005/247; H01L 23/00 20060101
H01L023/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 22, 2019 |
JP |
2019-081252 |
Claims
1. A wire shape measurement device for a semiconductor device,
which comprises: a substrate; a semiconductor element mounted on
the substrate; and a wire connecting an electrode of the
semiconductor element and an electrode of the substrate, or
connecting one electrode of the semiconductor element and another
electrode of the semiconductor element, the wire shape measurement
device comprising: a plurality of cameras capturing two-dimensional
images of the semiconductor device; and a control unit measuring a
shape of the wire based on the two-dimensional images of the
semiconductor device acquired by the cameras, wherein the control
unit: respectively captures the two-dimensional images of the
semiconductor device with the plurality of cameras, sets
two-dimensional coordinate detection regions at predetermined
intervals in a region that connects a start point and a terminal
point of connection of the wire with the substrate or the
semiconductor element in each of the two-dimensional images,
searches the two-dimensional coordinate detection regions for a
linear image corresponding to a diameter of the wire by pattern
matching that superimposes a reference pattern and a detected
image, repeats a plurality of times an operation of taking a center
position of the linear image corresponding to the diameter of the
wire as two-dimensional coordinates of the wire in the
two-dimensional coordinate detection region, and respectively
extracts two-dimensional coordinates corresponding to a portion of
the wire from the two-dimensional images of the semiconductor
device acquired by the cameras, calculates respective
three-dimensional coordinates of a plurality of portions of the
wire based on the two-dimensional coordinates respectively
extracted and a position of each of the cameras, generates a
three-dimensional image of the wire based on the three-dimensional
coordinates calculated, and measures the shape of the wire based on
the three-dimensional image of the wire generated.
2. (canceled)
3. (canceled)
4. The wire shape measurement device according to claim 1, wherein
the cameras are respectively arranged on both sides of the wire so
that optical axes of the cameras intersect a direction in which the
wire extends.
5. The wire shape measurement device according to claim 1, wherein
the control unit inspects the shape of the wire based on the
three-dimensional image of the wire generated.
6. The wire shape measurement device according to claim 5, wherein
the control unit inspects the shape of the wire by comparing the
three-dimensional image of the wire generated with a reference
shape of the wire.
7. The wire shape measurement device according to claim 6, wherein
the control unit: extracts a shape parameter of the wire from the
three-dimensional image of the wire generated, and inspects the
shape of the wire by comparing the shape parameter extracted with a
reference value of the shape parameter.
8. A wire three-dimensional image generation method for a
semiconductor device, which comprises: a substrate; a semiconductor
element mounted on the substrate; and a wire connecting an
electrode of the semiconductor element and an electrode of the
substrate, or connecting one electrode of the semiconductor element
and another electrode of the semiconductor element, the wire
three-dimensional image generation method comprising: an image
capturing step of respectively capturing two-dimensional images of
the semiconductor device with a plurality of cameras; a
two-dimensional coordinate extraction step of setting
two-dimensional coordinate detection regions at predetermined
intervals in a region that connects a start point and a terminal
point of connection of the wire with the substrate or the
semiconductor element in each of the two-dimensional images,
searching the two-dimensional coordinate detection regions for a
linear image corresponding to a diameter of the wire by pattern
matching that superimposes a reference pattern and a detected
image, repeating a plurality of times an operation of taking a
center position of the linear image corresponding to the diameter
of the wire as two-dimensional coordinates of the wire in the
two-dimensional coordinate detection region, and respectively
extracting two-dimensional coordinates corresponding to a portion
of the wire from the two-dimensional images of the semiconductor
device acquired by the cameras; a three-dimensional coordinate
calculation step of calculating respective three-dimensional
coordinates of a plurality of portions of the wire based on the
two-dimensional coordinates respectively extracted and a position
of each of the cameras; and a three-dimensional image generation
step of generating a three-dimensional image of the wire based on
the three-dimensional coordinates calculated.
9. (canceled)
10. (canceled)
11. A wire shape measurement method for a semiconductor device,
which comprises: a substrate; a semiconductor element mounted on
the substrate; and a wire connecting an electrode of the
semiconductor element and an electrode of the substrate, or
connecting one electrode of the semiconductor element and another
electrode of the semiconductor element, the wire shape measurement
method comprising: an image capturing step of respectively
capturing two-dimensional images of the semiconductor device with a
plurality of cameras; a two-dimensional coordinate extraction step
of setting two-dimensional coordinate detection regions at
predetermined intervals in a region that connects a start point and
a terminal point of connection of the wire with the substrate or
the semiconductor element in each of the two-dimensional images,
searching the two-dimensional coordinate detection regions for a
linear image corresponding to a diameter of the wire by pattern
matching that superimposes a reference pattern and a detected
image, repeating a plurality of times an operation of taking a
center position of the linear image corresponding to the diameter
of the wire as two-dimensional coordinates of the wire in the
two-dimensional coordinate detection region, and respectively
extracting two-dimensional coordinates corresponding to a portion
of the wire from the two-dimensional images of the semiconductor
device acquired by the cameras; a three-dimensional coordinate
calculation step of calculating respective three-dimensional
coordinates of a plurality of portions of the wire based on the
two-dimensional coordinates respectively extracted and a position
of each of the cameras; a three-dimensional image generation step
of generating a three-dimensional image of the wire based on the
three-dimensional coordinates calculated; and a measurement step of
measuring a shape of the wire based on the three-dimensional image
of the wire generated.
12. The wire shape measurement method according to claim 11,
comprising an inspection step of inspecting the shape of the wire
based on the three-dimensional image of the wire generated.
13. The wire shape measurement method according to claim 12,
wherein the inspection step inspects the shape of the wire by
comparing the three-dimensional image of the wire generated with a
reference shape of the wire.
14. The wire shape measurement method according to claim 13,
wherein the inspection step extracts a shape parameter of the wire
from the three-dimensional image of the wire generated, and
inspects the shape of the wire by comparing the shape parameter
extracted with a reference value of the shape parameter.
Description
BACKGROUND
Technical Field
[0001] The present invention relates to a wire shape measurement
device for measuring a shape of a wire that connects an electrode
of a semiconductor element mounted on a substrate and an electrode
of the substrate, a method for generating a three-dimensional image
of the wire, and a wire shape measurement method for measuring a
wire shape.
Description of Related Art
[0002] A loop shape of a bonding wire (hereinafter referred to as
wire) that connects a pad of a semiconductor chip and a lead of a
substrate is measured. A method of detecting XY coordinates of the
wire at a focusing height of an optical system to measure a
three-dimensional shape of the entire wire has been proposed as a
method for measuring the loop shape of the wire (see, for example,
Patent Document 1).
[0003] This method illuminates the wire with a ring-shaped
illuminator, captures wire images while changing the focusing
height using the optical system with a shallow depth of focus, and
detects a dark part that appears in the center of each wire image,
so as to detect the XY coordinates of the wire at each focusing
height and detect the three-dimensional shape of the entire wire
from the data.
RELATED ART
Patent Document
[0004] [Patent Document 1] Specification of Japanese Patent No.
3235009
SUMMARY
Problems to be Solved
[0005] In recent years, there has been a demand for measuring the
shapes of all the wires connecting the electrode of the
semiconductor chip and the electrode of the substrate. However,
according to the wire shape measurement method described in Patent
Document 1, it is necessary to capture a plurality of images by
changing the focusing height of the optical system, and therefore
the time required for the inspection is long.
[0006] Further, it is also required to improve the accuracy of wire
shape measurement. When the wire is illuminated with a ring-shaped
illuminator as in the conventional technology described in Patent
Document 1, in the portion where the wire extends in the
substantially horizontal direction in the image, the vicinity of
the center line of the wire at the focal point is dark and the
edges at both ends of the wire in the width direction are bright,
but in the portion where the wire is inclined, the vicinity of the
center line of the wire may be bright and the edges at both ends of
the wire in the width direction may be dark. Therefore, in the
conventional technology described in Patent Document 1, the
detection accuracy of the three-dimensional shape of the entire
wire may decrease for a wire having an inclined portion.
[0007] The present invention is to provide a wire shape measurement
device that is capable of measuring a shape of a wire with high
accuracy in a short time.
Means for Solving the Problems
[0008] A wire shape measurement device according to the present
invention is for a semiconductor device, which includes: a
substrate; a semiconductor element mounted on the substrate; and a
wire connecting an electrode of the semiconductor element and an
electrode of the substrate, or connecting one electrode of the
semiconductor element and another electrode of the semiconductor
element. The wire shape measurement device includes: a plurality of
cameras capturing two-dimensional images of the semiconductor
device; and a control unit measuring a shape of the wire based on
the two-dimensional images of the semiconductor device acquired by
the cameras. The control unit: generates a three-dimensional image
of the wire from the two-dimensional images of the semiconductor
device acquired by the cameras by pattern matching using connection
position information of a position where the wire is connected to
the substrate or the semiconductor element and thickness
information of the wire, and measures the shape of the wire based
on the three-dimensional image of the wire generated.
[0009] Since the three-dimensional image of the wire is generated
from the two-dimensional images of the semiconductor device
acquired by the cameras by pattern matching using the connection
position information of the position where the wire is connected to
the substrate or the semiconductor element and the thickness
information of the wire, the three-dimensional image can be
generated accurately in a short time. Thereby, the wire shape
measurement device capable of measuring the shape of the wire with
high accuracy in a short time can be provided.
[0010] In the wire shape measurement device according to the
present invention, the control unit may respectively extract
two-dimensional coordinates of each point in each two-dimensional
image corresponding to one portion of the wire from the
two-dimensional images of the semiconductor device acquired by the
cameras by using the connection position information of the
position where the wire is connected to the substrate or the
semiconductor element and the thickness information of the wire,
calculate three-dimensional coordinates of one portion of the wire
by using the two-dimensional coordinates extracted, and generate a
three-dimensional image of the wire based on the three-dimensional
coordinates calculated.
[0011] Further, in the wire shape measurement device according to
the present invention, the control unit may repeatedly respectively
extract two-dimensional coordinates of each point in each
two-dimensional image corresponding to one portion of the wire from
the two-dimensional images of the semiconductor device acquired by
the cameras by using the connection position information of the
position where the wire is connected to the substrate or the
semiconductor element and the thickness information of the wire
from a start end to a terminal end of the wire, to extract the
two-dimensional coordinates of each point in each two-dimensional
image respectively corresponding to a plurality of portions of the
wire, calculate three-dimensional coordinates of the plurality of
portions of the wire by using the two-dimensional coordinates in
each two-dimensional image respectively corresponding to the
plurality of portions of the wire extracted, and generate a
three-dimensional image from the start end to the terminal end of
the wire based on the three-dimensional coordinates of the
plurality of portions of the wire calculated.
[0012] Since the image of the wire is specified from the
two-dimensional images of the entire semiconductor device captured
by the cameras using the connection position information of the
position where the wire is connected to the substrate or the
semiconductor element and the thickness information of the wire,
and the two-dimensional coordinates of the point on the wire image
are extracted, the two-dimensional coordinates of the point on the
image of the wire can be extracted from the two-dimensional images
of the entire semiconductor device in a short time. Thereby, the
wire shape measurement device capable of measuring the shape of the
wire with high accuracy in a short time can be provided.
[0013] In the wire shape measurement device according to the
present invention, the cameras may be respectively arranged on both
sides of the wire so that optical axes of the cameras intersect a
direction in which the wire extends.
[0014] By arranging the cameras in this way, the difference in the
two-dimensional coordinates of each point in each two-dimensional
image corresponding to one portion of the wire captured by each
camera becomes large, the three-dimensional coordinates of one
portion of the wire can be calculated with high accuracy, and the
accuracy of measuring the shape of the wire can be improved.
[0015] In the wire shape measurement device according to the
present invention, the control unit may inspect the shape of the
wire based on the three-dimensional image of the wire generated,
the control unit may inspect the shape of the wire by comparing the
three-dimensional image of the wire generated with a reference
shape of the wire, and the control unit may extract a shape
parameter of the wire from the three-dimensional image of the wire
generated, and inspect the shape of the wire by comparing the shape
parameter extracted with a reference value of the shape
parameter.
[0016] Thereby, it is possible to perform various shape
measurements and shape inspections on the wire.
[0017] A wire three-dimensional image generation method according
to the present invention is for a semiconductor device, which
includes: a substrate; a semiconductor element mounted on the
substrate; and a wire connecting an electrode of the semiconductor
element and an electrode of the substrate, or connecting one
electrode of the semiconductor element and another electrode of the
semiconductor element. The wire three-dimensional image generation
method includes: an image capturing step of respectively capturing
two-dimensional images of the semiconductor device with a plurality
of cameras; and a three-dimensional image generation step of
generating a three-dimensional image of the wire from the
two-dimensional images of the semiconductor device acquired by the
cameras by pattern matching using connection position information
of a position where the wire is connected to the substrate or the
semiconductor element and thickness information of the wire.
[0018] Since the three-dimensional image of the wire is generated
from the two-dimensional images of the semiconductor device
acquired by the cameras by pattern matching using the connection
position information of the position where the wire is connected to
the substrate or the semiconductor element and the thickness
information of the wire, the three-dimensional image can be
generated accurately in a short time.
[0019] In the wire three-dimensional image generation method
according to the present invention, the three-dimensional image
generation step may include: a two-dimensional coordinate
extraction step of respectively extracting two-dimensional
coordinates of each point in each two-dimensional image
corresponding to one portion of the wire from the two-dimensional
images of the semiconductor device acquired by the cameras by using
the connection position information of the position where the wire
is connected to the substrate or the semiconductor element and the
thickness information of the wire; a three-dimensional coordinate
calculation step of calculating three-dimensional coordinates of
one portion of the wire by using the two-dimensional coordinates
extracted; and an image generation step of generating a
three-dimensional image of the wire based on the three-dimensional
coordinates calculated.
[0020] Further, in the wire three-dimensional image generation
method according to the present invention, the two-dimensional
coordinate extraction step may repeatedly respectively extract
two-dimensional coordinates of each point in each two-dimensional
image corresponding to one portion of the wire from the
two-dimensional images of the semiconductor device acquired by the
cameras by using the connection position information of the
position where the wire is connected to the substrate or the
semiconductor element and the thickness information of the wire
from a start end to a terminal end of the wire, to extract the
two-dimensional coordinates of each point in each two-dimensional
image respectively corresponding to a plurality of portions of the
wire. The three-dimensional coordinate calculation step may
calculate three-dimensional coordinates of the plurality of
portions of the wire by using the two-dimensional coordinates in
each two-dimensional image respectively corresponding to the
plurality of portions of the wire extracted. The image generation
step may generate a three-dimensional image from the start end to
the terminal end of the wire based on the three-dimensional
coordinates of the plurality of portions of the wire
calculated.
[0021] Since the image of the wire is specified from the
two-dimensional images of the entire semiconductor device captured
by the cameras using the connection position information of the
position where the wire is connected to the substrate or the
semiconductor element and the thickness information of the wire,
and the two-dimensional coordinates of the point on the wire image
are extracted, the two-dimensional coordinates of the point on the
image of the wire can be extracted from the two-dimensional images
of the entire semiconductor device in a short time.
[0022] A wire shape measurement method according to the present
invention is for a semiconductor device, which includes: a
substrate; a semiconductor element mounted on the substrate; and a
wire connecting an electrode of the semiconductor element and an
electrode of the substrate, or connecting one electrode of the
semiconductor element and another electrode of the semiconductor
element. The wire shape measurement method includes: an image
capturing step of respectively capturing two-dimensional images of
the semiconductor device with a plurality of cameras; a
three-dimensional image generation step of generating a
three-dimensional image of the wire from the two-dimensional images
of the semiconductor device acquired by the cameras by pattern
matching using connection position information of a position where
the wire is connected to the substrate or the semiconductor element
and thickness information of the wire; and a measurement step of
measuring a shape of the wire based on the three-dimensional image
of the wire generated.
[0023] Further, the wire shape measurement method according to the
present invention may include an inspection step of inspecting the
shape of the wire based on the three-dimensional image of the wire
generated, and the inspection step may inspect the shape of the
wire by comparing the three-dimensional image of the wire generated
with a reference shape of the wire. In addition, the inspection
step may extract a shape parameter of the wire from the
three-dimensional image of the wire generated, and inspect the
shape of the wire by comparing the shape parameter extracted with a
reference value of the shape parameter.
[0024] Thereby, it is possible to perform various shape
measurements and shape inspections on the wire.
Effects
[0025] The present invention can provide a wire shape measurement
device that is capable of measuring a shape of a wire with high
accuracy in a short time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is an elevational view showing the wire shape
measurement device according to the embodiment.
[0027] FIG. 2 is a plan view showing the wire shape measurement
device according to the embodiment.
[0028] FIG. 3 is a flowchart showing an operation of the wire shape
measurement device according to the embodiment.
[0029] FIG. 4 is a perspective view showing an arrangement of a
wire and cameras of the wire shape measurement device according to
the embodiment.
[0030] FIG. 5 is an explanatory view showing a two-dimensional
image acquired by imaging a wire with a camera arranged on the
Y-direction plus side of the semiconductor device of the wire shape
measurement device according to the embodiment.
[0031] FIG. 6 is an explanatory view showing a two-dimensional
image acquired by imaging a wire with a camera arranged on the
Y-direction minus side of the semiconductor device of the wire
shape measurement device according to the embodiment.
DESCRIPTION OF THE EMBODIMENTS
[0032] Hereinafter, a wire shape measurement device 100 according
to an embodiment will be described with reference to the drawings.
As shown in FIG. 1 and FIG. 2, the wire shape measurement device
100 is a device for measuring the shape of a wire 30 of a
semiconductor device 10, which includes a substrate 11, a
semiconductor element 20 mounted on the substrate 11, and the wire
30 connecting an electrode 25 of the semiconductor element 20 and
an electrode 12 of the substrate 11. The wire shape measurement
device 100 includes a plurality of cameras 41 to 44 that capture
two-dimensional images of the semiconductor device 10, and a
control unit 50 that inspects the shape of the wire 30 based on the
two-dimensional images acquired by the cameras 41 to 44. In the
following description, an X direction and a Y direction are
orthogonal to each other in a horizontal plane, and a Z direction
is a vertical direction.
[0033] As shown in FIG. 2, the cameras 41 and 42 are arranged so
that the optical axes 41a and 42a extend in the X direction, and
are arranged so as to image the semiconductor device 10 from
diagonally above in the X direction. Further, the cameras 43 and 44
are arranged so that the optical axes 43a and 44a extend in the Y
direction, and are arranged so as to image the semiconductor device
10 from diagonally above in the Y direction. Therefore, the cameras
41 and 42 are arranged on both sides of the wire 30 extending in
the Y direction so that the optical axes 41a and 42a intersect the
wire 30 extending in the Y direction, and the cameras 43 and 44 are
arranged on both sides of the wire 30 extending in the X direction
so that the optical axes 43a and 44a intersect the wire 30
extending in the X direction. Each of the cameras 41 to 44 is
connected to the control unit 50, and data of the image acquired by
each camera is input to the control unit 50. The control unit 50 is
a computer including a CPU 51 that processes information
internally, and a memory 52 that stores data, programs, etc.
[0034] Next, an operation of the wire shape measurement device 100
according to the embodiment will be described with reference to
FIG. 3 to FIG. 6. In the following description, as shown in FIG. 4,
a three-dimensional image of the wire 30 which extends in the X
direction between the electrode 25 of the semiconductor element 20
and the electrode 12 of the substrate 11 is generated based on a
two-dimensional image captured by the camera 43 arranged diagonally
above the wire 30 on the Y-direction plus side and a
two-dimensional image captured by the camera 44 arranged diagonally
above the wire 30 on the Y-direction minus side, and the shape of
the wire 30 extending in the X direction is inspected by using the
generated three-dimensional image. In FIG. 4, reference numerals 35
to 37 and 39 indicate portions of the wire 30 located in
two-dimensional coordinate detection regions 60 (described later
with reference to FIG. 5 and FIG. 6) for detecting two-dimensional
coordinates of the wire 30, which are set at predetermined
intervals AX in the middle of an X-axis that connects a start end
31 and a terminal end 32 of the wire 30.
[0035] As shown in step S101 of FIG. 3, the CPU 51 of the control
unit 50 reads the coordinates (xs, ys), (xe, ye) of the start end
31 of the wire 30 connected to the electrode 25 of the
semiconductor element 20 and the terminal end 32 connected to the
electrode 12 of the substrate 11 from the memory 52. Here, the
coordinates are connection position information of a position where
the wire 30 is connected to the semiconductor element 20. Further,
the CPU 51 of the control unit 50 reads a diameter of the wire 30
which is thickness information of the wire 30 from the memory
52.
[0036] Next, as shown in step S102 of FIG. 3, the control unit 50
captures images of the semiconductor device 10 with the cameras 43
and 44, and as shown in step S103 of FIG. 3, stores the captured
images in the memory 52.
[0037] When the wire 30 is imaged by the camera 43 arranged on the
Y-direction plus side of the semiconductor device 10, as shown in
FIG. 5, the two-dimensional image of the wire 30 acquired by the
camera 43 is an image curved toward the Y-direction minus side
according to the change in the height of the wire 30. Further, when
the wire 30 is imaged by the camera 44 arranged on the Y-direction
minus side of the semiconductor device 10, as shown in FIG. 6, the
two-dimensional image of the wire 30 acquired by the camera 44 is
an image curved toward the Y-direction plus side according to the
change in the height of the wire 30.
[0038] Next, as shown in step S104 of FIG. 3 and FIG. 5, the
control unit 50 sets the two-dimensional coordinate detection
regions 60 for detecting the two-dimensional coordinates of the
wire 30 at the predetermined intervals AX in the middle of the
X-axis that connects the start end 31 and the terminal end 32 of
the wire 30 in the image acquired by the camera 43. Then, as shown
in step S105 of FIG. 3, the control unit 50 searches the
two-dimensional coordinate detection regions 60 for a linear image
having a thickness the same as the diameter of the wire 30 by using
pattern matching. Then, when the control unit 50 detects an image
having a thickness the same as the diameter of the wire 30, the
control unit 50 acquires the two-dimensional coordinates of the
center point of the image as (x31, y31), (x32, y32), (x33, y33) and
stores them in the memory 52. The two-dimensional coordinates (x31,
y31), (x32, y32), (x33, y33) are two-dimensional coordinates
corresponding to the portions 35 to 36 of the wire 30 shown in FIG.
4. Then, the control unit 50 repeats the operation of acquiring the
two-dimensional coordinates from the start end 31 to the terminal
end 32, and acquires the two-dimensional coordinates (x31, y31) to
(x3e, y3e) of the center point of the image having a thickness the
same as the diameter of the wire 30 in all the two-dimensional
coordinate detection regions 60 from the start end 31 to the
terminal end 32. These two-dimensional coordinates are
two-dimensional coordinates corresponding to the portions 35 to 39
of the wire 30, respectively.
[0039] Similarly, as shown in FIG. 6, the control unit 50 sets the
two-dimensional coordinate detection regions 60 in the image
acquired by the camera 44, and searches the two-dimensional
coordinate detection regions 60 for a linear image having a
thickness the same as the diameter of the wire 30 by using pattern
matching. Then, when the control unit 50 detects an image having a
thickness the same as the diameter of the wire 30, the control unit
50 acquires the two-dimensional coordinates of the center point of
the image as (x41, y41) to (x4e, y4e) and stores them in the memory
52. These two-dimensional coordinates are two-dimensional
coordinates corresponding to the portions 35 to 39 of the wire 30,
respectively. Then, when the control unit 50 determines YES in step
S106 of FIG. 3, the control unit 50 proceeds to step S107 of FIG.
3.
[0040] Since the two-dimensional coordinates (x31, y31) acquired
from the image of the camera 43 and the two-dimensional coordinates
(x41, y41) acquired from the image of the camera 44 in step S105 of
FIG. 3 are two-dimensional coordinates corresponding to the same
portion 35 of the wire 30 shown in FIG. 4, three-dimensional
coordinates of the portion 35 of the wire 30 can be calculated from
the two two-dimensional coordinates and the positions of the
cameras 43 and 44. Similarly, since the two-dimensional coordinates
(x32, y32) and (x33, y33) acquired from the image of the camera 43
and the two-dimensional coordinates (x42, y42) and (x43, y43)
acquired from the image of the camera 44 are two-dimensional
coordinates corresponding to the same portions 36 and 37 of the
wire 30 shown in FIG. 4, three-dimensional coordinates of the
portions 36 and 37 of the wire 30 can be calculated from these
coordinates.
[0041] Therefore, in step S107 of FIG. 3, the control unit 50
calculates the three-dimensional coordinates of a plurality of
portions 35 to 39 from the start end 31 to the terminal end 32 of
the wire 30 shown in FIG. 4 based on the two-dimensional
coordinates (x31, y31) to (x3e, y3e) from the start end 31 to the
terminal end 32 of the wire 30 acquired by the camera 43, the
two-dimensional coordinates (x41, y41) to (x4e, y4e) from the start
end 31 to the terminal end 32 of the wire 30 acquired by the camera
44, and the positions of the cameras 43 and 44.
[0042] Then, in step S108 of FIG. 3, the control unit 50 connects
the three-dimensional coordinates of the plurality of portions 35
to 39 calculated to generate a three-dimensional image of the wire
30. Therefore, the three-dimensional image of the wire 30 is a
curve that is bent three-dimensionally.
[0043] In step S109 of FIG. 3, the control unit 50 measures the
dimensions of the shape of the wire 30 based on the generated
three-dimensional image of the wire 30. Further, the control unit
50 compares the generated three-dimensional image of the wire 30
with a reference shape such as a reference loop shape of the wire
30 to detect the difference between the two dimensions, and
determines that the shape of the wire 30 is abnormal if the
difference exceeds a predetermined threshold value.
[0044] In addition, the control unit 50 may also measure the shape
parameters of the wire 30 from the generated three-dimensional
image of the wire 30, for example, the shape dimensions such as the
loop height which is the height from the start end 31 of the wire
30, the thickness of the crimp ball formed at the start end 31, the
diameter of the crimp ball, etc., and compare each measured shape
dimension with a reference value to perform the inspection.
[0045] As described above, since the wire shape measurement device
100 can generate the three-dimensional image of the wire 30 from
the two-dimensional images of the semiconductor device 10 acquired
by the cameras 43 and 44 by pattern matching using the
two-dimensional coordinates (xs, ys) and (xe, ye) of the start end
31 and the terminal end 32 of the wire 30 and the diameter of the
wire 30, the three-dimensional image can be generated accurately in
a short time. Thus, it is possible to perform shape measurement and
shape inspection on the wire 30 with high accuracy in a short
time.
[0046] After inspection of the shape of the wire 30 extending in
the Y direction, shape measurement and shape inspection are
performed by performing the same processing based on the
two-dimensional images captured by the cameras 41 and 42.
[0047] Furthermore, the two-dimensional images acquired by the four
cameras 41 to 44, instead of the two cameras 41 and 42 or the two
cameras 43 and 44, may be processed to generate the
three-dimensional image of the wire 30. In addition, the
two-dimensional images of four or more cameras may be processed to
generate the three-dimensional image of the wire 30.
[0048] The above-described embodiment illustrates that the wire 30
for shape measurement or shape inspection connects the electrode 25
of the semiconductor element 20 and the electrode 12 of the
substrate 11, but the present invention is not limited thereto. For
example, the present invention can also be applied to the
inspection of the shape of the wire 30 that continuously connects
the electrode 25 of the semiconductor element 20 of each layer, the
electrode 25 of the semiconductor element 20 of the lowermost
layer, and the electrode 12 of the substrate 11 in the
semiconductor device 10 which laminates a plurality of
semiconductor elements 20 on the substrate 11. In such a case, the
wire 30 connects one electrode 25 of the semiconductor element 20
of one layer and another electrode 25 of the semiconductor element
20 of another layer, and connects the electrode 25 of the
semiconductor element 20 of the lowermost layer and the electrode
12 of the substrate 11.
[0049] Further, when a wire shape measurement method is executed
using the wire shape measurement device 100 according to the
embodiment, capturing the two-dimensional images of the
semiconductor device 10 with the cameras and storing them in the
memory 52, as shown in steps S102 and S103 shown in FIG. 3,
corresponds to an image capturing step. Further, generating the
three-dimensional image of the wire 30 from the captured
two-dimensional images, as shown in steps S104 to S108 of FIG. 3,
constitutes a three-dimensional image generation step, and
measuring the shape of the wire 30 based on the three-dimensional
image, as shown in step S109 of FIG. 3, constitutes a measurement
step. In addition, inspecting the shape of the wire 30 based on the
three-dimensional image, as shown in step S109 of FIG. 3,
constitutes an inspection step.
[0050] Further, the step of extracting the two-dimensional
coordinates, as in steps S104 to S106 of FIG. 3, constitutes a
two-dimensional coordinate extraction step; the step of calculating
the three-dimensional coordinates based on the extracted
two-dimensional coordinates, as shown in step S107 of FIG. 3,
constitutes a three-dimensional coordinate calculation step; and
the step of generating the three-dimensional image of the wire 30
from the calculated three-dimensional coordinates, as shown in step
S108 of FIG. 3, constitutes an image generation step.
[0051] Further, when a wire three-dimensional image generation
method is executed using the wire shape measurement device 100
according to the embodiment, capturing the two-dimensional images
of the semiconductor device 10 with the cameras and storing them in
the memory 52, as shown in steps S102 and S103 of FIG. 3,
corresponds to the image capturing step. In addition, generating
the three-dimensional image of the wire 30 from the captured
two-dimensional images, as shown in steps S104 to S108 of FIG. 3,
constitutes the three-dimensional image generation step.
DESCRIPTIONS OF REFERENCE NUMERALS
[0052] 10 semiconductor device; 11 substrate; 12, 25 electrode; 20
semiconductor element; 30 wire; 31 start end; 32 terminal end; 41
to 44 camera; 41a to 44a optical axis; 50 control unit; 51 CPU; 52
memory; 60 two-dimensional coordinate detection region; 100 wire
shape measurement device.
* * * * *